A computer network is a collection of interconnected computing devices that can exchange data and share resources. Often, in highly populated areas, the computer network is configured in a ring formation, where certain devices, such as layer 2 devices, e.g., a switch, are interconnected via network links in a ring. That is, each layer 2 device couples via a separate network link to two adjacent layer 2 devices, one clockwise and the other counter-clockwise around the ring. It should be noted that layer 2 refers to the data link layer of the Open Systems Interconnection Reference Model (OSI Reference Model or OSI Model). When arranged in a ring, a network, e.g., an optical fiber network, a copper network, or a combination of both, is referred to as a “ring network.”
Generally, access nodes, subtending from a layer 2 device, provide access to the ring network. Access nodes, such as a Digital Line Subscriber Line Access Multiplexer (DSLAM), a Cable Modem Termination System (CMTS), and a Passive Optical Network (PON) optical line terminal (OLT), for example, each manage access by one or more of the computing devices to the ring network. The access node may, for example, multiplex (or “aggregate”) traffic from computing devices into a composite signal and transmit this signal to a switch on the ring network for delivery to one or more destinations.
The computing devices couple to the access nodes to gain access to the ring network and thereby interconnect with other computing devices coupled to the ring network via access nodes. The computing devices generate data traffic and exchange this data traffic with other computing devices via the interconnection provided by the ring network. The layer 2 devices forward the data traffic typically in a determined direction, e.g., clockwise or counter-clockwise, around the ring to facilitate the exchange. The ring network may provide generous geographical coverage due to its topology, which allows the ring network to reach computing devices dispersed over wide geographical areas. The ring network may be resilient in that it can forward data in both the clockwise and counter-clockwise directions to avoid a faulted link.